Image forming apparatus and optical sensor with multiple light-receiving and light-emitting elements

Abstract

An image forming apparatus includes an optical sensor configured to detect an image formed on an intermediate transfer belt. The optical sensor includes a first light emitting diode (LED), a second LED, a first photodiode (PD), and a second PD on a substrate. The first PD is arranged at a position at which specularly reflected light of light emitted from the first LED can be received, and scattered reflected light of light emitted from the second LED can be received. The second PD is arranged at a position at which scattered reflected light of light emitted from the second LED can be received. A light receiving surface of the first PD and a light receiving surface of the second PD are formed at different angles. The light receiving surface of the first PD has an area that is smaller than an area of the light receiving surface of the second PD.

Description

BACKGROUND OF THE INVENTIONField of the Invention[0001]The present disclosure relates to an optical sensor including a plurality of light emitting elements configured to irradiate an image bearing member with light, and a plurality of light receiving elements configured to receive reflected light of light emitted from the plurality of light emitting elements, and to an image forming apparatus including the optical sensor.Description of the Related Art[0002]An electrophotographic image forming apparatus is configured to form images of colors of yellow (Y), magenta (M), cyan (C), and black (K) on a sheet through electrophotographic processes of charging, exposing, developing, and transferring. Densities of the images formed on the sheet are varied depending on temperature and humidity of the image forming apparatus, the number of prints of the image forming apparatus, and operating time of the image forming apparatus. To address this problem, the image forming apparatus is configured ...

AI Technical Summary

Problems solved by technology

Therefore, when image forming positions of the yellow image, the magenta image, the cyan image, and the black image are different, a tint of the image of the mixed colors does not become a desired tint.

Hei 10-031333 is assembled by soldering bullet light emitting elements and bullet light receiving elements on a substrate, and hence it is difficult to reduce the size of the optical sensor.

Further, when a light receiving element for detecting color misregistration and a light receiving element for detecting an image density are to be mounted on one sensor, possible arrangements of those light receiving elements is restricted, and hence it is difficult for the optical sensor to receive reflected light at an ideal angle from the detection image.

Therefore, in the image forming apparatus including the optical sensor including the bullet element for detecting color misregistration and the bullet element for detecting the image density, there has been a fear that a color misregistration amount and an image density cannot be detected with high accuracy.

However, the image to be formed on a sheet and the detection image are formed on the same image bearing member, and hence when the conveyance speed of the image bearing member is reduced to form the detection image, down time is disadvantageously increased.

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